Genus: Magnimus SIGOGNEAU-RUSSELL, 1999
Etymology: Latin, magus, "grand" and Latin, mus, "mouse."

Species: ensomi SIGOGNEAU-RUSSELL, 1999
Etymology: In honor of P. Ensom.

Holotype: DORCM GS 627

Locality: Sunnydown Farm, near Langton Matravrs, Dorset County, England, Southern United Kingdom.

Horizon: Cherry Freshwater Member, Lulworth Formation, Purbeck Limestone Group.

Biostratigraphy:

Age: ?Berriasian Stage, Lower Neocomian Subepoch, Lower Early Cretaceous Epoch, Early Cretaceous.

Material: Upper second molar.

Referred material:

DORCM GS 332: Lower second molar.

DORCM GS 621: Left lower molar.